Former secretary of state shares stories from new memoir during Politics & Prose, GW event.

Hillary Rodham Clinton is saying exactly what’s on her mind these days.

The former first lady, senator and secretary of state said she’s “totally done” with being overly cautious about expressing herself, especially after reflecting on her experiences while writing the new memoir “Hard Choices.” Ms. Clinton’s career negotiating some of the world’s toughest conflicts taught her that neither “shouting matches nor biting one’s tongue” render much. Instead, she believes in the power of straightforward conversations and honest opinions.

“The perspective I’ve gained has encouraged me even more to speak to my mind and contribute what I can,” she said.

Embracing her appreciation for sincerity, Ms. Clinton had a candid conversation with former Clinton speechwriter and staffer Lissa Muscatine on Friday at Lisner Auditorium. The event was sponsored by the George Washington University and Politics & Prose, which Ms. Muscatine co-owns. Eager guests and friends of Ms. Clinton filled the sold-out auditorium, giving her a warm welcome back to Washington, D.C.

Writing “Hard Choices” came at a transitional period in Ms. Clinton’s life, just after she had left her position as secretary of state. Her goal was to give Americans an accurate account of her time as a senior government official. Although she had the luxury of a more flexible schedule, Ms. Clinton found penning the book a difficult task and was often distracted by other chores—walking the dog, grabbing a drink of water. Still, she labored over each page, writing most of it by hand on legal paper in the attic of her New York farmhouse.

“What I tried to do in the book is to give the reader a bit of a peek behind the curtain, because the headlines certainly tell some of the story—but not all of the story,” she said.

“Hard Choices” has been hailed for showcasing a lighthearted side of Ms. Clinton, but its anecdotes show that she’s always had a knack for bringing personality to even the most critical situations. Take, for example, when she met Saudi Arabia’s King Abdullah. Because she’d heard his foreign minister disliked camels, she began a friendly banter with the leader.

“I said, ‘Your majesty, did you know the foreign minister doesn’t like camels?’ And he said, ‘What is wrong with him!’ ” Ms. Clinton remembered. After some laughs, the two sat down for a meeting and covered ground on serious business. It provided Ms. Clinton a lesson in how Americans should embrace patience rather than just quick diplomacy and establish a repertoire before immediately negotiating.

“We’d actually interacted as two people, not two officials in a hurry,” she remembered.

As she tended to a broad level of crises at home and overseas, Ms. Clinton explained that one of her primary roles as secretary of state was to boost America’s reputation abroad and reinforce that the U.S. was committed to being a consequential part of decision-making across the globe. In Asia, she wanted to demonstrate alliances; in Europe, she wanted to rebuild relationships.

“It was a multitasking of the highest order to try to be present, reach out, come up with new ideas and make clear that America’s presence and leadership was going to be front and center,” she said.

It also required shifting gears very quickly. Ms. Clinton recalled a meeting in Lima, Peru, to finalize sanctions that the UN Security Council would impose on Iran. China’s buy-in was critical, and she wanted to secure some face-time with the Chinese foreign ambassador. Convinced she wouldn’t get to meet with him, Ms. Clinton stopped by a press happy hour, where reporters were enjoying pisco sours. A couple drinks in, the Chinese foreign ambassador showed up, and Ms. Clinton had to instantly revert to diplomatic mode. The two began poring over the lines of the UN agreement—but not before White House correspondent Mark Landler brought them a couple more cocktails.

Although her days are no longer stacked with back-to-back meetings with foreign leaders, Ms. Clinton is keeping a watchful eye on international developments, particularly in Iraq. President Barack Obama recently decided to hold off on military intervention as militant Sunni fighters threaten a government helmed by Shiite Prime Minister Nuri al-Maliki. The situation is complex and could potentially spill over into neighboring regions in the Middle East, but Ms. Clinton said Prime Minister al-Maliki’s flawed governance is a major problem, and it is imperative that the U.S. receive a specific set of conditions before discussing involvement.

“That’s a delicate and difficult task for our government because we certainly don’t want to fight the fight, because you’d be fighting for the dysfunctional, unrepresentative, authoritarian government. There’s no reason on earth that I know of that you would sacrifice a single American life for that,” she said.

While Ms. Muscatine didn't directly ask if Ms. Clinton will campaign for president in 2016, the two did discuss the legacy that the former secretary of state hopes to leave for both the American people and her future granddaughter, who is due this fall. Enthusiasts hoping Ms. Clinton will become America's first female president interpreted her answer as a potential clue that she’ll run and immediately burst into applause.

“I’m not ready to stop and think about legacy because I want to keep thinking about what my life has meant to me and what my obligations are to my grandchild and everyone else, and I’m going to do that through the work of the Clinton Foundation—and other ways,” Ms. Clinton said.